Merge pull request #78598 from BastiaanOlij/resolve_depth_buffer_mobile

Resolve depth buffer in mobile renderer when required

doc/classes/RenderingDevice.xml

@@ -2014,6 +2014,9 @@
 		<constant name="TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT" value="4" enum="TextureUsageBits" is_bitfield="true">
 			Texture can be used as a depth/stencil attachment in a framebuffer.
 		</constant>
+		<constant name="TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT" value="4096" enum="TextureUsageBits" is_bitfield="true">
+			Texture can be used as a depth/stencil resolve attachment in a framebuffer.
+		</constant>
 		<constant name="TEXTURE_USAGE_STORAGE_BIT" value="8" enum="TextureUsageBits" is_bitfield="true">
 			Texture can be used as a [url=https://registry.khronos.org/vulkan/specs/1.3-extensions/html/vkspec.html#descriptorsets-storageimage]storage image[/url].
 		</constant>

drivers/vulkan/rendering_device_driver_vulkan.cpp

@@ -536,6 +536,7 @@ Error RenderingDeviceDriverVulkan::_initialize_device_extensions() {
 	_register_requested_device_extension(VK_KHR_BUFFER_DEVICE_ADDRESS_EXTENSION_NAME, false);
 	_register_requested_device_extension(VK_KHR_VULKAN_MEMORY_MODEL_EXTENSION_NAME, false);
 	_register_requested_device_extension(VK_EXT_TEXTURE_COMPRESSION_ASTC_HDR_EXTENSION_NAME, false);
+	_register_requested_device_extension(VK_KHR_DEPTH_STENCIL_RESOLVE_EXTENSION_NAME, false);
 
 	// We don't actually use this extension, but some runtime components on some platforms
 	// can and will fill the validation layers with useless info otherwise if not enabled.
@@ -746,6 +747,9 @@ Error RenderingDeviceDriverVulkan::_check_device_capabilities() {
 	device_capabilities.version_major = VK_API_VERSION_MAJOR(physical_device_properties.apiVersion);
 	device_capabilities.version_minor = VK_API_VERSION_MINOR(physical_device_properties.apiVersion);
 
+	// Cache extension availability we query often.
+	framebuffer_depth_resolve = enabled_device_extension_names.has(VK_KHR_DEPTH_STENCIL_RESOLVE_EXTENSION_NAME);
+
 	// References:
 	// https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_KHR_multiview.html
 	// https://www.khronos.org/blog/vulkan-subgroup-tutorial
@@ -2012,7 +2016,7 @@ RDD::TextureID RenderingDeviceDriverVulkan::texture_create(const TextureFormat &
 	if ((p_format.usage_bits & TEXTURE_USAGE_COLOR_ATTACHMENT_BIT)) {
 		create_info.usage |= VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
 	}
-	if ((p_format.usage_bits & TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT)) {
+	if ((p_format.usage_bits & (TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT))) {
 		create_info.usage |= VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT;
 	}
 	if ((p_format.usage_bits & TEXTURE_USAGE_INPUT_ATTACHMENT_BIT)) {
@@ -2103,7 +2107,7 @@ RDD::TextureID RenderingDeviceDriverVulkan::texture_create(const TextureFormat &
 	image_view_create_info.components.a = (VkComponentSwizzle)p_view.swizzle_a;
 	image_view_create_info.subresourceRange.levelCount = create_info.mipLevels;
 	image_view_create_info.subresourceRange.layerCount = create_info.arrayLayers;
-	if ((p_format.usage_bits & TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT)) {
+	if ((p_format.usage_bits & (TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT))) {
 		image_view_create_info.subresourceRange.aspectMask = VK_IMAGE_ASPECT_DEPTH_BIT;
 	} else {
 		image_view_create_info.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
@@ -2484,6 +2488,7 @@ BitField<RDD::TextureUsageBits> RenderingDeviceDriverVulkan::texture_get_usages_
 	}
 	if (!(flags & VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT)) {
 		supported.clear_flag(TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT);
+		supported.clear_flag(TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT);
 	}
 	if (!(flags & VK_FORMAT_FEATURE_STORAGE_IMAGE_BIT)) {
 		supported.clear_flag(TEXTURE_USAGE_STORAGE_BIT);
@@ -4876,12 +4881,32 @@ RDD::RenderPassID RenderingDeviceDriverVulkan::render_pass_create(VectorView<Att
 			VkFragmentShadingRateAttachmentInfoKHR *vk_fsr_info = ALLOCA_SINGLE(VkFragmentShadingRateAttachmentInfoKHR);
 			*vk_fsr_info = {};
 			vk_fsr_info->sType = VK_STRUCTURE_TYPE_FRAGMENT_SHADING_RATE_ATTACHMENT_INFO_KHR;
+			vk_fsr_info->pNext = vk_subpasses[i].pNext;
 			vk_fsr_info->pFragmentShadingRateAttachment = vk_subpass_fsr_attachment;
 			vk_fsr_info->shadingRateAttachmentTexelSize.width = p_subpasses[i].fragment_shading_rate_texel_size.x;
 			vk_fsr_info->shadingRateAttachmentTexelSize.height = p_subpasses[i].fragment_shading_rate_texel_size.y;
 
 			vk_subpasses[i].pNext = vk_fsr_info;
 		}
+
+		// Depth resolve.
+		if (framebuffer_depth_resolve && p_subpasses[i].depth_resolve_reference.attachment != AttachmentReference::UNUSED) {
+			VkAttachmentReference2KHR *vk_subpass_depth_resolve_attachment = ALLOCA_SINGLE(VkAttachmentReference2KHR);
+			*vk_subpass_depth_resolve_attachment = {};
+			vk_subpass_depth_resolve_attachment->sType = VK_STRUCTURE_TYPE_ATTACHMENT_REFERENCE_2_KHR;
+			vk_subpass_depth_resolve_attachment->attachment = p_subpasses[i].depth_resolve_reference.attachment;
+			vk_subpass_depth_resolve_attachment->layout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
+
+			VkSubpassDescriptionDepthStencilResolveKHR *vk_depth_resolve_info = ALLOCA_SINGLE(VkSubpassDescriptionDepthStencilResolveKHR);
+			*vk_depth_resolve_info = {};
+			vk_depth_resolve_info->sType = VK_STRUCTURE_TYPE_SUBPASS_DESCRIPTION_DEPTH_STENCIL_RESOLVE;
+			vk_depth_resolve_info->pNext = vk_subpasses[i].pNext;
+			vk_depth_resolve_info->depthResolveMode = VK_RESOLVE_MODE_MAX_BIT_KHR;
+			vk_depth_resolve_info->stencilResolveMode = VK_RESOLVE_MODE_NONE_KHR; // we don't resolve our stencil (for now)
+			vk_depth_resolve_info->pDepthStencilResolveAttachment = vk_subpass_depth_resolve_attachment;
+
+			vk_subpasses[i].pNext = vk_depth_resolve_info;
+		}
 	}
 
 	VkSubpassDependency2KHR *vk_subpass_dependencies = ALLOCA_ARRAY(VkSubpassDependency2KHR, p_subpass_dependencies.size());
@@ -6269,6 +6294,8 @@ bool RenderingDeviceDriverVulkan::has_feature(Features p_feature) {
 #endif
 		case SUPPORTS_VULKAN_MEMORY_MODEL:
 			return vulkan_memory_model_support && vulkan_memory_model_device_scope_support;
+		case SUPPORTS_FRAMEBUFFER_DEPTH_RESOLVE:
+			return framebuffer_depth_resolve;
 		default:
 			return false;
 	}

drivers/vulkan/rendering_device_driver_vulkan.h

@@ -137,6 +137,7 @@ class RenderingDeviceDriverVulkan : public RenderingDeviceDriver {
 	bool vulkan_memory_model_device_scope_support = false;
 	bool pipeline_cache_control_support = false;
 	bool device_fault_support = false;
+	bool framebuffer_depth_resolve = false;
 #if defined(VK_TRACK_DEVICE_MEMORY)
 	bool device_memory_report_support = false;
 #endif

modules/openxr/extensions/platform/openxr_vulkan_extension.cpp

@@ -343,15 +343,15 @@ bool OpenXRVulkanExtension::get_swapchain_image_data(XrSwapchain p_swapchain, in
 			break;
 		case VK_FORMAT_D32_SFLOAT:
 			format = RenderingDevice::DATA_FORMAT_D32_SFLOAT;
-			usage_flags |= RenderingDevice::TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT;
+			usage_flags |= RenderingDevice::TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | RenderingDevice::TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT;
 			break;
 		case VK_FORMAT_D24_UNORM_S8_UINT:
 			format = RenderingDevice::DATA_FORMAT_D24_UNORM_S8_UINT;
-			usage_flags |= RenderingDevice::TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT;
+			usage_flags |= RenderingDevice::TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | RenderingDevice::TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT;
 			break;
 		case VK_FORMAT_D32_SFLOAT_S8_UINT:
 			format = RenderingDevice::DATA_FORMAT_D32_SFLOAT_S8_UINT;
-			usage_flags |= RenderingDevice::TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT;
+			usage_flags |= RenderingDevice::TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | RenderingDevice::TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT;
 			break;
 		default:
 			// continue with our default value

servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.cpp

@@ -194,7 +194,7 @@ RID RendererSceneRenderImplementation::RenderForwardMobile::RenderBufferDataForw
 	return RID();
 }
 
-RID RenderForwardMobile::RenderBufferDataForwardMobile::get_color_fbs(FramebufferConfigType p_config_type) {
+RID RenderForwardMobile::RenderBufferDataForwardMobile::get_color_fbs(FramebufferConfigType p_config_type, bool p_resolve_depth) {
 	ERR_FAIL_NULL_V(render_buffers, RID());
 
 	RendererRD::TextureStorage *texture_storage = RendererRD::TextureStorage::get_singleton();
@@ -225,17 +225,22 @@ RID RenderForwardMobile::RenderBufferDataForwardMobile::get_color_fbs(Framebuffe
 
 	Vector<RID> textures;
 	int color_buffer_id = 0;
-	textures.push_back(use_msaa ? render_buffers->get_color_msaa() : render_buffers->get_internal_texture()); // 0 - color buffer
-	textures.push_back(use_msaa ? render_buffers->get_depth_msaa() : render_buffers->get_depth_texture()); // 1 - depth buffer
+	int depth_buffer_id = 1;
+	textures.push_back(use_msaa ? render_buffers->get_color_msaa() : render_buffers->get_internal_texture()); // 0 - color buffer.
+	textures.push_back(use_msaa ? render_buffers->get_depth_msaa() : render_buffers->get_depth_texture()); // 1 - depth buffer.
 	if (vrs_texture.is_valid()) {
-		textures.push_back(vrs_texture); // 2 - vrs texture
+		textures.push_back(vrs_texture); // 2 - vrs texture.
 	}
 	if (use_msaa) {
 		color_buffer_id = textures.size();
-		textures.push_back(render_buffers->get_internal_texture()); // color buffer for resolve
+		textures.push_back(render_buffers->get_internal_texture()); // Color buffer for resolve.
+	}
+	if (use_msaa && p_resolve_depth) {
+		depth_buffer_id = textures.size();
+		textures.push_back(render_buffers->get_depth_texture()); // Depth buffer for resolve.
 	}
 
-	// Now define our subpasses
+	// Now define our subpasses.
 	Vector<RD::FramebufferPass> passes;
 
 	switch (p_config_type) {
@@ -245,8 +250,13 @@ RID RenderForwardMobile::RenderBufferDataForwardMobile::get_color_fbs(Framebuffe
 			pass.depth_attachment = 1;
 
 			if (use_msaa) {
-				// Add resolve
+				// Add color resolve.
 				pass.resolve_attachments.push_back(color_buffer_id);
+
+				if (p_resolve_depth) {
+					// Add depth resolve.
+					pass.depth_resolve_attachment = depth_buffer_id;
+				}
 			}
 			passes.push_back(pass);
 
@@ -257,7 +267,7 @@ RID RenderForwardMobile::RenderBufferDataForwardMobile::get_color_fbs(Framebuffe
 			Size2i target_size = render_buffers->get_target_size();
 			Size2i internal_size = render_buffers->get_internal_size();
 
-			// can't do our blit pass if resolutions don't match, this should already have been checked.
+			// Can't do our blit pass if resolutions don't match, this should already have been checked.
 			ERR_FAIL_COND_V(target_size != internal_size, RID());
 
 			RD::FramebufferPass pass;
@@ -265,13 +275,18 @@ RID RenderForwardMobile::RenderBufferDataForwardMobile::get_color_fbs(Framebuffe
 			pass.depth_attachment = 1;
 
 			if (use_msaa) {
-				// add resolve
+				// Add color resolve.
 				pass.resolve_attachments.push_back(color_buffer_id);
+
+				if (p_resolve_depth) {
+					// Add depth resolve.
+					pass.depth_resolve_attachment = depth_buffer_id;
+				}
 			}
 
 			passes.push_back(pass);
 
-			// - add blit to 2D pass
+			// Add blit to 2D pass.
 			RID render_target = render_buffers->get_render_target();
 			ERR_FAIL_COND_V(render_target.is_null(), RID());
 			RID target_buffer;
@@ -284,12 +299,12 @@ RID RenderForwardMobile::RenderBufferDataForwardMobile::get_color_fbs(Framebuffe
 			ERR_FAIL_COND_V(target_buffer.is_null(), RID());
 
 			int target_buffer_id = textures.size();
-			textures.push_back(target_buffer); // target buffer
+			textures.push_back(target_buffer); // Target buffer.
 
 			RD::FramebufferPass blit_pass;
-			blit_pass.input_attachments.push_back(color_buffer_id); // Read from our (resolved) color buffer
-			blit_pass.color_attachments.push_back(target_buffer_id); // Write into our target buffer
-			// this doesn't need VRS
+			blit_pass.input_attachments.push_back(color_buffer_id); // Read from our (resolved) color buffer.
+			blit_pass.color_attachments.push_back(target_buffer_id); // Write into our target buffer.
+			// This doesn't need VRS or depth.
 			passes.push_back(blit_pass);
 
 			return FramebufferCacheRD::get_singleton()->get_cache_multipass(textures, passes, view_count);
@@ -807,9 +822,13 @@ void RenderForwardMobile::_render_scene(RenderDataRD *p_render_data, const Color
 
 	RENDER_TIMESTAMP("Setup 3D Scene");
 
+	bool has_depth_texture_override = false;
+	bool supports_depth_resolve = RenderingDevice::get_singleton()->has_feature(RD::SUPPORTS_FRAMEBUFFER_DEPTH_RESOLVE);
+
 	RID render_target = rb->get_render_target();
 	if (render_target.is_valid()) {
-		p_render_data->scene_data->calculate_motion_vectors = RendererRD::TextureStorage::get_singleton()->render_target_get_override_velocity(render_target).is_valid();
+		p_render_data->scene_data->calculate_motion_vectors = texture_storage->render_target_get_override_velocity(render_target).is_valid();
+		has_depth_texture_override = texture_storage->render_target_get_override_depth(render_target).is_valid();
 	} else {
 		p_render_data->scene_data->calculate_motion_vectors = false;
 	}
@@ -834,6 +853,7 @@ void RenderForwardMobile::_render_scene(RenderDataRD *p_render_data, const Color
 
 	RS::ViewportMSAA msaa = rb->get_msaa_3d();
 	bool use_msaa = msaa != RS::VIEWPORT_MSAA_DISABLED;
+	bool resolve_depth_buffer = (use_msaa && has_depth_texture_override); // We'll check more conditions later.
 
 	bool ce_has_post_opaque = _has_compositor_effect(RS::COMPOSITOR_EFFECT_CALLBACK_TYPE_POST_OPAQUE, p_render_data);
 	bool ce_has_pre_transparent = _has_compositor_effect(RS::COMPOSITOR_EFFECT_CALLBACK_TYPE_PRE_TRANSPARENT, p_render_data);
@@ -937,6 +957,7 @@ void RenderForwardMobile::_render_scene(RenderDataRD *p_render_data, const Color
 		if (use_msaa && p_render_data->environment.is_valid() && RSG::camera_attributes->camera_attributes_uses_dof(p_render_data->camera_attributes)) {
 			// Need to resolve depth texture for DOF when using MSAA.
 			scene_state.used_depth_texture = true;
+			resolve_depth_buffer = true;
 		}
 
 		if (scene_state.used_screen_texture || scene_state.used_depth_texture) {
@@ -945,13 +966,17 @@ void RenderForwardMobile::_render_scene(RenderDataRD *p_render_data, const Color
 			using_subpass_post_process = false;
 		}
 
+		if (use_msaa && (global_surface_data.depth_texture_used || scene_state.used_depth_texture)) {
+			resolve_depth_buffer = true;
+		}
+
 		if (using_subpass_post_process) {
 			// We can do all in one go.
-			framebuffer = rb_data->get_color_fbs(RenderBufferDataForwardMobile::FB_CONFIG_RENDER_AND_POST_PASS);
+			framebuffer = rb_data->get_color_fbs(RenderBufferDataForwardMobile::FB_CONFIG_RENDER_AND_POST_PASS, resolve_depth_buffer && supports_depth_resolve);
 			global_pipeline_data_required.use_subpass_post_pass = true;
 		} else {
 			// We separate things out.
-			framebuffer = rb_data->get_color_fbs(RenderBufferDataForwardMobile::FB_CONFIG_RENDER_PASS);
+			framebuffer = rb_data->get_color_fbs(RenderBufferDataForwardMobile::FB_CONFIG_RENDER_PASS, resolve_depth_buffer && supports_depth_resolve);
 			global_pipeline_data_required.use_separate_post_pass = true;
 		}
 		samplers = rb->get_samplers();
@@ -1242,8 +1267,6 @@ void RenderForwardMobile::_render_scene(RenderDataRD *p_render_data, const Color
 				RD::get_singleton()->draw_command_end_label(); // Render Transparent Subpass
 			}
 
-			// note if we are using MSAA we should get an automatic resolve through our subpass configuration.
-
 			// blit to tonemap
 			if (rb_data.is_valid() && using_subpass_post_process) {
 				_post_process_subpass(p_render_data->render_buffers->get_internal_texture(), framebuffer, p_render_data);
@@ -1252,6 +1275,13 @@ void RenderForwardMobile::_render_scene(RenderDataRD *p_render_data, const Color
 			RD::get_singleton()->draw_command_end_label(); // Render 3D Pass / Render Reflection Probe Pass
 
 			RD::get_singleton()->draw_list_end();
+
+			// note, if MSAA is used we should get an automatic resolve of the color buffer here.
+
+			if (use_msaa && has_depth_texture_override && !supports_depth_resolve) {
+				// We don't have a fallback for this, See PR #111322
+				WARN_PRINT_ONCE("MSAA Depth buffer resolve is not supported on this platform.");
+			}
 		} else {
 			// We're done with our subpasses so end our container pass
 			// note, if MSAA is used we should get an automatic resolve of the color buffer here.
@@ -1274,12 +1304,17 @@ void RenderForwardMobile::_render_scene(RenderDataRD *p_render_data, const Color
 				}
 			}
 
+			if (use_msaa && has_depth_texture_override && !supports_depth_resolve) {
+				// We don't have a fallback for this, See PR #111322
+				WARN_PRINT_ONCE("MSAA Depth buffer resolve is not supported on this platform.");
+			}
+
 			if (scene_state.used_depth_texture || global_surface_data.depth_texture_used) {
 				_render_buffers_ensure_depth_texture(p_render_data);
 
 				if (scene_state.used_depth_texture) {
 					// Copy depth texture to backbuffer so we can read from it.
-					_render_buffers_copy_depth_texture(p_render_data, use_msaa);
+					_render_buffers_copy_depth_texture(p_render_data, use_msaa && !supports_depth_resolve); // Note, once fallback for has_depth_texture_override works, we also don't need to do our resolve here.
 				}
 			}
 

servers/rendering/renderer_rd/forward_mobile/render_forward_mobile.h

@@ -86,7 +86,7 @@ private:
 			FB_CONFIG_MAX
 		};
 
-		RID get_color_fbs(FramebufferConfigType p_config_type);
+		RID get_color_fbs(FramebufferConfigType p_config_type, bool p_resolve_depth = false);
 		virtual void free_data() override;
 		virtual void configure(RenderSceneBuffersRD *p_render_buffers) override;
 

servers/rendering/renderer_rd/framebuffer_cache_rd.h

@@ -58,6 +58,7 @@ class FramebufferCacheRD : public Object {
 
 	static _FORCE_INLINE_ uint32_t _hash_pass(const RD::FramebufferPass &p, uint32_t h) {
 		h = hash_murmur3_one_32(p.depth_attachment, h);
+		h = hash_murmur3_one_32(p.depth_resolve_attachment, h);
 
 		h = hash_murmur3_one_32(p.color_attachments.size(), h);
 		for (int i = 0; i < p.color_attachments.size(); i++) {
@@ -82,6 +83,10 @@ class FramebufferCacheRD : public Object {
 			return false;
 		}
 
+		if (a.depth_resolve_attachment != b.depth_resolve_attachment) {
+			return false;
+		}
+
 		if (a.color_attachments.size() != b.color_attachments.size()) {
 			return false;
 		}

servers/rendering/renderer_rd/storage_rd/render_scene_buffers_rd.cpp

@@ -730,7 +730,11 @@ uint32_t RenderSceneBuffersRD::get_color_usage_bits(bool p_resolve, bool p_msaa,
 }
 
 RD::DataFormat RenderSceneBuffersRD::get_depth_format(bool p_resolve, bool p_msaa, bool p_storage) {
-	if (p_resolve) {
+	// TODO Our rendering engine does not support just having a depth attachment, it always assumed we combine with stencil.
+	// We thus can't configure our depth resolve with RD::DATA_FORMAT_R32_SFLOAT.
+	// We should add support for TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT or add a TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT
+
+	if (p_resolve && !RenderingDevice::get_singleton()->has_feature(RD::SUPPORTS_FRAMEBUFFER_DEPTH_RESOLVE)) {
 		return RD::DATA_FORMAT_R32_SFLOAT;
 	} else {
 		const RenderingDeviceCommons::DataFormat preferred_formats[2] = {
@@ -749,7 +753,13 @@ uint32_t RenderSceneBuffersRD::get_depth_usage_bits(bool p_resolve, bool p_msaa,
 	if (p_msaa) {
 		usage_bits |= RD::TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | RD::TEXTURE_USAGE_CAN_COPY_FROM_BIT;
 	} else if (p_resolve) {
-		usage_bits |= RD::TEXTURE_USAGE_CAN_COPY_TO_BIT | (p_storage ? RD::TEXTURE_USAGE_STORAGE_BIT : 0);
+		usage_bits |= RD::TEXTURE_USAGE_CAN_COPY_TO_BIT;
+		if (p_storage) {
+			usage_bits |= RD::TEXTURE_USAGE_STORAGE_BIT;
+		} else if (RenderingDevice::get_singleton()->has_feature(RD::SUPPORTS_FRAMEBUFFER_DEPTH_RESOLVE)) {
+			// We're able to resolve depth in (sub)passes and we make use of this in our mobile renderer.
+			usage_bits |= RD::TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT;
+		}
 	} else {
 		usage_bits |= RD::TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT;
 	}

servers/rendering/rendering_device.cpp

@@ -1080,7 +1080,7 @@ RID RenderingDevice::texture_create(const TextureFormat &p_format, const Texture
 	texture.allowed_shared_formats = format.shareable_formats;
 	texture.has_initial_data = !data.is_empty();
 
-	if ((format.usage_bits & TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT)) {
+	if ((format.usage_bits & (TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT))) {
 		texture.read_aspect_flags.set_flag(RDD::TEXTURE_ASPECT_DEPTH_BIT);
 		texture.barrier_aspect_flags.set_flag(RDD::TEXTURE_ASPECT_DEPTH_BIT);
 		if (format_has_stencil(format.format)) {
@@ -1094,7 +1094,7 @@ RID RenderingDevice::texture_create(const TextureFormat &p_format, const Texture
 	texture.bound = false;
 
 	// Textures are only assumed to be immutable if they have initial data and none of the other bits that indicate write usage are enabled.
-	bool texture_mutable_by_default = texture.usage_flags & (TEXTURE_USAGE_COLOR_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | TEXTURE_USAGE_STORAGE_BIT | TEXTURE_USAGE_STORAGE_ATOMIC_BIT);
+	bool texture_mutable_by_default = texture.usage_flags & (TEXTURE_USAGE_COLOR_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT | TEXTURE_USAGE_STORAGE_BIT | TEXTURE_USAGE_STORAGE_ATOMIC_BIT);
 	if (data.is_empty() || texture_mutable_by_default) {
 		_texture_make_mutable(&texture, RID());
 	}
@@ -1225,7 +1225,7 @@ RID RenderingDevice::texture_create_from_extension(TextureType p_type, DataForma
 	texture.allowed_shared_formats.push_back(RD::DATA_FORMAT_R8G8B8A8_UNORM);
 	texture.allowed_shared_formats.push_back(RD::DATA_FORMAT_R8G8B8A8_SRGB);
 
-	if (p_usage.has_flag(TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT)) {
+	if (p_usage.has_flag(TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT) || p_usage.has_flag(TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT)) {
 		texture.read_aspect_flags.set_flag(RDD::TEXTURE_ASPECT_DEPTH_BIT);
 		texture.barrier_aspect_flags.set_flag(RDD::TEXTURE_ASPECT_DEPTH_BIT);
 		/*if (format_has_stencil(p_format.format)) {
@@ -1236,7 +1236,7 @@ RID RenderingDevice::texture_create_from_extension(TextureType p_type, DataForma
 		texture.barrier_aspect_flags.set_flag(RDD::TEXTURE_ASPECT_COLOR_BIT);
 	}
 
-	texture.driver_id = driver->texture_create_from_extension(p_image, p_type, p_format, p_layers, (texture.usage_flags & TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT), p_mipmaps);
+	texture.driver_id = driver->texture_create_from_extension(p_image, p_type, p_format, p_layers, (texture.usage_flags & (TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT)), p_mipmaps);
 	ERR_FAIL_COND_V(!texture.driver_id, RID());
 
 	_texture_make_mutable(&texture, RID());
@@ -2468,7 +2468,7 @@ RDD::RenderPassID RenderingDevice::_render_pass_create(RenderingDeviceDriver *p_
 
 		ERR_FAIL_INDEX_V(p_attachments[i].format, DATA_FORMAT_MAX, RDD::RenderPassID());
 		ERR_FAIL_INDEX_V(p_attachments[i].samples, TEXTURE_SAMPLES_MAX, RDD::RenderPassID());
-		ERR_FAIL_COND_V_MSG(!(p_attachments[i].usage_flags & (TEXTURE_USAGE_COLOR_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | TEXTURE_USAGE_INPUT_ATTACHMENT_BIT | TEXTURE_USAGE_VRS_ATTACHMENT_BIT)),
+		ERR_FAIL_COND_V_MSG(!(p_attachments[i].usage_flags & (TEXTURE_USAGE_COLOR_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT | TEXTURE_USAGE_INPUT_ATTACHMENT_BIT | TEXTURE_USAGE_VRS_ATTACHMENT_BIT)),
 				RDD::RenderPassID(), "Texture format for index (" + itos(i) + ") requires an attachment (color, depth-stencil, input or VRS) bit set.");
 
 		RDD::Attachment description;
@@ -2501,6 +2501,13 @@ RDD::RenderPassID RenderingDevice::_render_pass_create(RenderingDeviceDriver *p_
 				description.stencil_store_op = p_store_ops[i];
 				description.initial_layout = RDD::TEXTURE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
 				description.final_layout = RDD::TEXTURE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
+			} else if (p_attachments[i].usage_flags & TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT) {
+				description.load_op = p_load_ops[i];
+				description.store_op = p_store_ops[i];
+				description.stencil_load_op = p_load_ops[i];
+				description.stencil_store_op = p_store_ops[i];
+				description.initial_layout = RDD::TEXTURE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
+				description.final_layout = RDD::TEXTURE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
 			} else {
 				description.load_op = RDD::ATTACHMENT_LOAD_OP_DONT_CARE;
 				description.store_op = RDD::ATTACHMENT_STORE_OP_DONT_CARE;
@@ -2613,6 +2620,21 @@ RDD::RenderPassID RenderingDevice::_render_pass_create(RenderingDeviceDriver *p_
 				ERR_FAIL_COND_V_MSG(texture_samples != p_attachments[attachment].samples, RDD::RenderPassID(), "Invalid framebuffer depth format attachment(" + itos(attachment) + "), in pass (" + itos(i) + "), if an attachment is marked as multisample, all of them should be multisample and use the same number of samples including the depth.");
 			}
 
+			if (pass->depth_resolve_attachment != ATTACHMENT_UNUSED) {
+				attachment = pass->depth_resolve_attachment;
+
+				// As our fallbacks are handled outside of our pass, we should never be setting up a render pass with a depth resolve attachment when not supported.
+				ERR_FAIL_COND_V_MSG(!p_driver->has_feature(SUPPORTS_FRAMEBUFFER_DEPTH_RESOLVE), RDD::RenderPassID(), "Invalid framebuffer depth format attachment(" + itos(attachment) + "), in pass (" + itos(i) + "), a depth resolve attachment was supplied when driver doesn't support this feature.");
+
+				ERR_FAIL_INDEX_V_MSG(attachment, p_attachments.size(), RDD::RenderPassID(), "Invalid framebuffer depth resolve format attachment(" + itos(attachment) + "), in pass (" + itos(i) + "), depth resolve attachment.");
+				ERR_FAIL_COND_V_MSG(!(p_attachments[attachment].usage_flags & TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT), RDD::RenderPassID(), "Invalid framebuffer depth resolve format attachment(" + itos(attachment) + "), in pass (" + itos(i) + "), it's marked as depth, but it's not a depth resolve attachment.");
+				ERR_FAIL_COND_V_MSG(attachment_last_pass[attachment] == i, RDD::RenderPassID(), "Invalid framebuffer depth resolve format attachment(" + itos(attachment) + "), in pass (" + itos(i) + "), it already was used for something else before in this pass.");
+
+				subpass.depth_resolve_reference.attachment = attachment_remap[attachment];
+				subpass.depth_resolve_reference.layout = RDD::TEXTURE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
+				attachment_last_pass[attachment] = i;
+			}
+
 		} else {
 			subpass.depth_stencil_reference.attachment = RDD::AttachmentReference::UNUSED;
 			subpass.depth_stencil_reference.layout = RDD::TEXTURE_LAYOUT_UNDEFINED;
@@ -2757,6 +2779,8 @@ RenderingDevice::FramebufferFormatID RenderingDevice::framebuffer_format_create(
 	for (int i = 0; i < p_format.size(); i++) {
 		if (p_format[i].usage_flags & TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT) {
 			pass.depth_attachment = i;
+		} else if (p_format[i].usage_flags & TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT) {
+			pass.depth_resolve_attachment = i;
 		} else {
 			pass.color_attachments.push_back(i);
 		}
@@ -2903,6 +2927,8 @@ RID RenderingDevice::framebuffer_create(const Vector<RID> &p_texture_attachments
 
 		if (texture && texture->usage_flags & TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT) {
 			pass.depth_attachment = i;
+		} else if (texture && texture->usage_flags & TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT) {
+			pass.depth_resolve_attachment = i;
 		} else if (texture && texture->usage_flags & TEXTURE_USAGE_VRS_ATTACHMENT_BIT) {
 			// Prevent the VRS attachment from being added to the color_attachments.
 		} else {
@@ -3661,7 +3687,7 @@ RID RenderingDevice::uniform_set_create(const VectorView<RD::Uniform> &p_uniform
 					ERR_FAIL_COND_V_MSG(!(texture->usage_flags & TEXTURE_USAGE_SAMPLING_BIT), RID(),
 							"Texture (binding: " + itos(uniform.binding) + ", index " + itos(j) + ") needs the TEXTURE_USAGE_SAMPLING_BIT usage flag set in order to be used as uniform.");
 
-					if ((texture->usage_flags & (TEXTURE_USAGE_COLOR_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | TEXTURE_USAGE_INPUT_ATTACHMENT_BIT))) {
+					if ((texture->usage_flags & (TEXTURE_USAGE_COLOR_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT | TEXTURE_USAGE_INPUT_ATTACHMENT_BIT))) {
 						UniformSet::AttachableTexture attachable_texture;
 						attachable_texture.bind = set_uniform.binding;
 						attachable_texture.texture = texture->owner.is_valid() ? texture->owner : uniform.get_id(j + 1);
@@ -3707,7 +3733,7 @@ RID RenderingDevice::uniform_set_create(const VectorView<RD::Uniform> &p_uniform
 					ERR_FAIL_COND_V_MSG(!(texture->usage_flags & TEXTURE_USAGE_SAMPLING_BIT), RID(),
 							"Texture (binding: " + itos(uniform.binding) + ", index " + itos(j) + ") needs the TEXTURE_USAGE_SAMPLING_BIT usage flag set in order to be used as uniform.");
 
-					if ((texture->usage_flags & (TEXTURE_USAGE_COLOR_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | TEXTURE_USAGE_INPUT_ATTACHMENT_BIT))) {
+					if ((texture->usage_flags & (TEXTURE_USAGE_COLOR_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT | TEXTURE_USAGE_INPUT_ATTACHMENT_BIT))) {
 						UniformSet::AttachableTexture attachable_texture;
 						attachable_texture.bind = set_uniform.binding;
 						attachable_texture.texture = texture->owner.is_valid() ? texture->owner : uniform.get_id(j);
@@ -4490,7 +4516,7 @@ RenderingDevice::DrawListID RenderingDevice::draw_list_begin(RID p_framebuffer,
 			resource_usages.push_back(RDG::RESOURCE_USAGE_ATTACHMENT_COLOR_READ_WRITE);
 			stages.set_flag(RDD::PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT);
 			color_index++;
-		} else if (texture->usage_flags & TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT) {
+		} else if (texture->usage_flags & (TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT)) {
 			if (p_draw_flags.has_flag(DRAW_CLEAR_DEPTH) || p_draw_flags.has_flag(DRAW_CLEAR_STENCIL)) {
 				operation = RDG::ATTACHMENT_OPERATION_CLEAR;
 				clear_value.depth = p_clear_depth_value;
@@ -5222,6 +5248,9 @@ void RenderingDevice::draw_list_end() {
 		if (texture->usage_flags & TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT) {
 			texture->bound = false;
 		}
+		if (texture->usage_flags & TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT) {
+			texture->bound = false;
+		}
 	}
 
 	draw_list_bound_textures.clear();
@@ -7986,6 +8015,7 @@ void RenderingDevice::_bind_methods() {
 	BIND_BITFIELD_FLAG(TEXTURE_USAGE_SAMPLING_BIT);
 	BIND_BITFIELD_FLAG(TEXTURE_USAGE_COLOR_ATTACHMENT_BIT);
 	BIND_BITFIELD_FLAG(TEXTURE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT);
+	BIND_BITFIELD_FLAG(TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT);
 	BIND_BITFIELD_FLAG(TEXTURE_USAGE_STORAGE_BIT);
 	BIND_BITFIELD_FLAG(TEXTURE_USAGE_STORAGE_ATOMIC_BIT);
 	BIND_BITFIELD_FLAG(TEXTURE_USAGE_CPU_READ_BIT);

servers/rendering/rendering_device.h

@@ -518,6 +518,7 @@ public:
 		Vector<int32_t> resolve_attachments;
 		Vector<int32_t> preserve_attachments;
 		int32_t depth_attachment = ATTACHMENT_UNUSED;
+		int32_t depth_resolve_attachment = ATTACHMENT_UNUSED;
 	};
 
 	typedef int64_t FramebufferFormatID;

servers/rendering/rendering_device_commons.h

@@ -421,7 +421,8 @@ public:
 		// Try to set this bit as much as possible. If you set it, validation doesn't complain
 		// and it works fine on mobile, then go ahead.
 		TEXTURE_USAGE_TRANSIENT_BIT = (1 << 11),
-		TEXTURE_USAGE_MAX_BIT = TEXTURE_USAGE_TRANSIENT_BIT,
+		TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT = (1 << 12),
+		TEXTURE_USAGE_MAX_BIT = TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT,
 	};
 
 	struct TextureFormat {
@@ -970,6 +971,7 @@ public:
 		SUPPORTS_BUFFER_DEVICE_ADDRESS,
 		SUPPORTS_IMAGE_ATOMIC_32_BIT,
 		SUPPORTS_VULKAN_MEMORY_MODEL,
+		SUPPORTS_FRAMEBUFFER_DEPTH_RESOLVE,
 	};
 
 	enum SubgroupOperations {

servers/rendering/rendering_device_driver.h

@@ -618,6 +618,7 @@ public:
 		LocalVector<AttachmentReference> input_references;
 		LocalVector<AttachmentReference> color_references;
 		AttachmentReference depth_stencil_reference;
+		AttachmentReference depth_resolve_reference;
 		LocalVector<AttachmentReference> resolve_references;
 		LocalVector<uint32_t> preserve_attachments;
 		AttachmentReference fragment_shading_rate_reference;